The law does not specify an age at which parents can leave children alone, but those who do can be arrested and prosecuted for cruelty and neglect if it places them at risk.

Justine Roberts, founder of Mumsnet, said the question of when a child was old enough to be left at home alone comes up “time and again” on the parenting website.

Chris Cloke, head of child protection awareness at the NSPCC, said: “Although there’s no legal minimum age for leaving children at home alone, no-one should leave a child unattended if they think they’ll be at risk.

“And it’s never acceptable to leave babies and very young children on their own for any length of time.”

Across the country, 105 mums and dads are facing police probes for leaving their children without supervision in the same time period.

All 43 police forces in England and Wales were asked how many parents were arrested in October, November and December last year, after leaving their children at home alone.

Figures included arrests for cruelty and neglect or abandoning a child. In a number of cases, both parents were arrested, but Merseyside Police did not provide further information on the five cases.

A spokesman for the Association of Chief Police Officers said: “There is no current legislation that gives a clear definition of when leaving a child on their own at home would constitute child neglect. However, the law is clear that you should never leave a child at home if they would be left at risk.”